English
Related papers

Related papers: Breathing Black Hole Shadows in Modified Gravity (…

200 papers

In this work, we investigate the observable optical signatures of the Mod(A)Max black hole spacetime. We analyze key optical features, including the photon sphere, black hole shadow, and photon trajectories, and examine how these…

General Relativity and Quantum Cosmology · Physics 2026-02-03 Faizuddin Ahmed , Ahmad Al-Badawi , Edilberto O. Silva

In this work, we introduce a novel framework to investigate ringdown gravitational waveforms in the presence of dynamical matter fields outside the horizon of a black hole. We systematically analyze two distinct scenarios of dynamical…

General Relativity and Quantum Cosmology · Physics 2026-01-26 Ying-Lei Tian , Hao Yang , Chen Lan , Yan-Gang Miao

We study the black hole's shadow for Schwarzschild - de Sitter and Kerr - de Sitter metrics with the contribution of the cosmological constant \Lambda. Based on the reported parameters of the M87* black hole shadow we obtain constraints for…

General Relativity and Quantum Cosmology · Physics 2021-01-29 A. Stepanian , Sh. Khlghatyan , V. G. Gurzadyan

Dynamical Chern-Simons (dCS) gravity is a promising extension of general relativity (GR), arising naturally from the low-energy limit of some string motivated theories. Even though dCS possesses an additional scalar degree of freedom,…

General Relativity and Quantum Cosmology · Physics 2018-11-07 Caio F. B. Macedo

Two new observational windows have been opened to strong gravitational physics: gravitational waves, and very long baseline interferometry. This suggests observational searches for new phenomena in this regime, and in particular for those…

General Relativity and Quantum Cosmology · Physics 2019-08-07 Steven B. Giddings , Seth Koren , Gabriel Treviño

In this work, by a novel approach to studying the scattering of a Schwarzschild black hole, the non-commutativity is introduced as a perturbation. We begin by reformulating the Klein-Gordon equation for the scalar field in a new form that…

General Relativity and Quantum Cosmology · Physics 2024-06-07 N. Heidari , H. Hassanabadi , A. A. Araújo Filho , J. Kuríuz

The Lorentzian-Euclidean black hole has been recently introduced as a geodesically complete spacetime featuring a signature shift at the event horizon where causal geodesics are precluded from reaching the central $r=0$ singularity. In this…

General Relativity and Quantum Cosmology · Physics 2026-05-08 Emmanuele Battista , Salvatore Capozziello , Che-Yu Chen

The polarized images of a synchrotron emitting ring are studied in the spacetime of a rotating black hole in the Scalar-Tensor-Vector-Gravity (STVG) theory. The black hole owns an additional dimensionless MOG parameter described its…

General Relativity and Quantum Cosmology · Physics 2022-10-26 Xin Qin , Songbai Chen , Zelin Zhang , Jiliang Jing

According to the no-hair theorem, static black holes are described by a Schwarzschild spacetime provided there are no other sources of the gravitational field. This requirement, however, is in astrophysical realistic scenarios often…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Norman Gürlebeck

We study black hole shadows in nonminimally coupled Weyl connection gravity, a metric-affine extension of general relativity in which spacetime is described by a metric and a Weyl vector field encoding non-metricity. Despite going beyond…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Cláudio Gomes , Margarida Lima , Francisco S. N. Lobo , Luís F. D. da Silva

We develop a perturbation theory for surfaces confining photons and massive particles in static spherically symmetric spacetimes in terms of two parameters: the mass-to-energy ratio and the deviation of metric functions from a given form,…

General Relativity and Quantum Cosmology · Physics 2024-10-22 Kirill Kobialko , Dmitri Gal'tsov

In this work, we study the motion of massive test particles and the gravitational--wave emission associated with periodic trajectories around a magnetically charged black hole immersed in a \textit{Hernquist} dark matter halo. We begin by…

General Relativity and Quantum Cosmology · Physics 2026-04-15 N. Heidari , A. A. Araujo Filho , Iarley P. Lobo

Recent shadow images of Sgr A and M87 captured by Event Horizon Telescope (EHT) collaboration confirms the existence of black holes or their possible alternatives in the center of galaxies. On the other hand, the new image of Sgr A in…

General Relativity and Quantum Cosmology · Physics 2024-08-16 Fateme Aliyan , Kourosh Nozari

Schwarzschild (non-rotating and chargeless) black holes are classically understood to be voids of extreme gravitation. In this study, we propose a holographic model for their interiors, envisioning them instead as a hydrodynamic medium.…

General Physics · Physics 2025-05-05 Noah M. MacKay

In the work, we have presented detailed analyses of the event horizon and curvature properties of spacetime around a regular black hole in modified gravity so-called regular MOG black hole. The motion of neutral, electrically charged and…

General Relativity and Quantum Cosmology · Physics 2020-10-27 Javlon Rayimbaev , Pulat Tadjimuratov , Ahmadjon Abdujabbarov , Bobomurat Ahmedov , Malika Khudoyberdieva

In this paper, the shadows cast by non-rotating and rotating modified gravity black holes are investigated. In addition to the black hole spin parameter $a$ and the inclination angle $\theta$ of observer, another parameter $\alpha$…

General Relativity and Quantum Cosmology · Physics 2019-04-08 Hui-Min Wang , Yu-Meng Xu , Shao-Wen Wei

We derive a relativistic field equation for the trace of the metric perturbation beyond the weak field approximation to the Einstein field equations. The dynamics is governed by a massive Klein-Gordon equation on curved space-time, where…

General Physics · Physics 2025-05-02 Victor Atanasov , Avadh Saxena

Observations of the black hole shadow of supermassive black holes, such as Sagittarius A* at the center of our Milky Way galaxy, allow us to study the properties of black holes and the nature of strong-field gravity. According to the Kerr…

General Relativity and Quantum Cosmology · Physics 2018-11-14 Dimitry Ayzenberg , Nicolas Yunes

This paper investigates the photon ring and shadow structure of the Reissner-Nordstr\"om black hole in the scalar-tensor-vector gravitational framework. The black hole is characterized by the ( MOG) parameter (\alpha) and the charge (Q).…

General Relativity and Quantum Cosmology · Physics 2026-02-04 Qiao Yue , Zhaoyi Xu , Meirong Tang

Ultralight bosonic fields are compelling dark-matter candidates and arise in a variety of beyond-Standard-Model scenarios. These fields can tap energy and angular momentum from spinning black holes through superradiant instabilities, during…

General Relativity and Quantum Cosmology · Physics 2020-06-04 Richard Brito , Sara Grillo , Paolo Pani